The present invention relates to an apparatus for manufacturing containers, and in particular relates to a mechanism for manually adjusting the angular position of rotating components of a container manufacturing process.
Metal beverage cans are designed and manufactured to withstand high internal pressure—typically 90 or 100 psi. Can bodies are commonly formed from a metal blank that is first drawn into a cup. The bottom of the cup is formed into a dome and a standing ring, and the sides of the cup are ironed to a desired can wall thickness and height. After the can is filled, a can end is placed onto the open can end and affixed with a seaming process.
It has been the conventional practice to reduce the diameter at the top of the can to reduce the weight of the can end in a process referred to as necking. Cans can be necked in a “spin necking” process in which cans are rotated with rollers that reduce the diameter of the neck. Most cans are necked in a “die necking” process in which cans are longitudinally pushed into dies to gently reduce the neck diameter over several stages. For example, reducing the diameter of a can neck from a conventional body diameter of 2 11/16th inches to 2 6/16th inches (that is, from a 211 to a 206 size) often requires multiple stages, often 14.
Each of the necking stages typically includes a main turret shaft that carries a starwheel for holding the can bodies, a die assembly that includes the tooling for reducing the diameter of the open end of the can, and a pusher ram to push the can into the die tooling. Each necking stage also typically includes a transfer turret assembly to transfer can bodies between turret starwheels. Transfer turret assemblies typically include a rotating transfer starwheel that includes a plurality of pockets that each retain a received can body under a vacuum pressure force. The rotating starwheel receives can bodies from a first operation stage, and delivers the can bodies to a second operation stage.
From time to time, it can become necessary or desirable to perform routine maintenance or repair maintenance on various rotatable components of the manufacturing process. However, because the manufacturing process components can be disposed in close proximity to each other, one component may interfere with the ability to provide maintenance on a neighboring rotatable component. For instance, when one wishes to access a desired location on one of the rotatable components, that location may not be easily accessible due to interference with a neighboring component, or because the user may be required to assume an awkward posture to access the desired location. As a result, it has become desirable to rotate the rotatable component to a desired angular position that removes the desired location from interference with neighboring process components, and that allows a user to easily access the desired location.